964 not starting - suspected flywheel sensor / crankshaft sensor

[stevehurst]

Hi everyone,
I had an issue with my 964 suddenly not started, backfiring, and struggling to fire. Looked into this and it seems the logical way forward was the flywheel sensor. So have fitted the new 996 style flywheel sensor, along with the new clip, and set the gap to 0.9mm using feeler gauges, and very crazed hands, but the car is still not sparking, although I do get a spark on the coils when the ignition is first turned on. When turning over, nothing. Tried pin 47 & 48 when turning over with a multimeter, to see if any signals to the ecu and nothing. I tested continuity of the wires and they are ok. What else can I test to see if the sensor is working? or set the gap in a different way may be?
Logic says, it's either; the gap, a faulty new sensor, or an ecu fault?
My gut feel is still the sensor or gap?
How or where can I get my ecu tested? When it first started playing up, it was a bit intermittent on starting with the occasional back fire. Any help and guidance greatly appreciated.
Thanks, Steve
Happy 964ing

 

[stevehurst]

Hi Everyone,
So have reset the flywheel sensor, and now getting 5volts ac on turning over, but still not starting.
Seems to not spark, so thinking may be an ecu fault.
How critical are the numbers on the outside of the ecu box?
There seems to be quite a few variations, across the 1989 to 1993, and not in a logical order.
Where would be a good place to get it tested?
Thanks,
Steve

 

[Stephenjk]

I don't know if this is any help but Phil from the driftworks YouTube channel replaced the crank sensor recently in his 964 turbo (2 or 3 964 videos ago) and had problems starting and running. He ended up running a much smaller gap I think 0.5mm though he had a new ECU as well. If you are getting a reading it probably isn't that but does sound unlikely ECU and sensor would fail together unless original sensor was fine and it was ECU all along.


On ECU repairs I'd try one of big Porsche garages like rpm and ask them if they repair or if not who they use. If isn't something I've seen commonly asked (unlike CCU or spoiler).

 

[stevehurst]

Thanks Stephen

 

[stevehurst]

Latest on my 964 non start issues.
Sent the ECU (911.618.124.03) off for testing and they cannot read it to check or repair.
Is this common?#
I have access to a durametric, and connected and it also says it cannot connect, but does this mean the ECU is faulty, or just not reading?
So far have replaced;
Coils, amplifiers, spark plugs, ignition leads,
and crankshaft sensor for the later 996 one, with wiring clip. I am getting 4.8v across pins 47 & 48 on ECU connector, so that seems to be working.
I changed DME relay just in case, no difference.
So reading further, the DME relay should start the fuel pump, and supply 12v to the ECU via pin 37?
Will check this next, is there a ground pin for the ecu I can check?
Thanks,
Steve